50 Pressure from Velocity. 50 of 95.
50/INPUT/50 of 95
Pressure from Velocity
When pressure is missing, motion can impersonate it.
Best experienced with a pointer.
The problem
Without a pressure sensor, strokes stay the same width whether you draw slowly or quickly, so ink never feels physical.
The solution
Derived pressure from velocity thins fast strokes and thickens slow ones; hardware pressure is shown separately when available.
Experiment
Play with the values
0.55
0.45
0.35
0.15
0.95
How it works
- Pointer speed is measured when the device does not report pressure.
- Speed is mapped to a stand-in pressure: slow reads as heavier, fast as lighter.
- Smoothing keeps that derived pressure from flickering between samples.
- Stroke width is computed from the derived pressure.
- The path is rendered at a variable width, while real hardware pressure stays a separate signal when it exists.
Seen in
Drawing apps
Mouse and trackpad strokes still feel pressure-sensitive when velocity stands in for force.
Note apps
Handwriting weight varies with pace even without a stylus pressure channel.
Signature pads
Fast flourishes thin out while deliberate strokes stay heavier.
Whiteboards
Freehand marks respond to motion when hardware pressure is absent.